The electrolytes so far known for use in the electronic components mentioned above include, among others, electrolytes for aluminum electrolytic capacitors such as those containing, as a solute, a quaternary ammonium salt of an aromatic carboxylic acid (e.g. phthalic acid) (U.S. Pat. No. 4,715,976), those containing, as a solute, a quaternary ammonium salt of maleic acid (U.S. Pat. No. 4,715,976) and those containing, as a solute, a quaternary ammonium salt of an aliphatic saturated dicarboxylic acid (U.S. Pat. No. 4,473,864).
Also known as electrolytes for electric double layer capacitors are those containing, as a solute, a quaternary ammonium salt of perchloric acid (Japanese Kokoku Publication Sho-54-9704), among others.
With the miniaturization, weight saving and high-density packaging of electronic devices and equipments in recent years, the production of electronic components in the form of chips has been increased. However, in this field of utilization, the electrolytes mentioned above are poor in thermal resistance and, to cope with the demand for chips, contrivances have been made only with respect to the sheathing material for intercepting heat from the outside or with respect to the method of sealing. In view of the expected further increase of chip-form production and the planar packaging of large electronic components in the future, the soldering temperature is expected to become higher, hence an electrolyte having thermal resistance at the reflow soldering temperature is earnestly desired.
Another problem is that when aluminum electrolytic capacitors or electric double layer capacitors are constructed using the above-mentioned electrolytes and a rubber sealant, the excess hydroxide ion formed by electrolysis of the quaternary salts on the negative potential electrode side causes degradation of the rubber sealing member, leading to marked deterioration of the sealing performance.
Accordingly, it is an object of the present invention to provide an electrolyte capable of meeting such requirements, namely an electrolyte having higher thermal resistance, high specific conductivity, excellent durability, free of the risk of causing sealing member deterioration, as well as providing an electronic component in which such electrolyte is used.